SRP and Full-mouth disinfection (FDIS) has been introduced to increase the success rate of SRP. FDIS is an adjunct therapy whereby scaling and root planing is performed within a 48 hour time frame to reduce the possibility for re-infection of the treated root surfaces. Chlorhexidine is used as a disinfectant in addition to the mechanical treatment. In a series of pilot studies on FDIS (Quirynen et al 1995, 1999, 2000, 2006, Bollen et al 1996) reported amazingly good results. On the other hand, Apatzidou et al a, b, c, (2004), Koshy et al (2005) and Wennström et al (2005) could not find any improvement from FDIS over conventional therapy.